【原创】科研训练指导手册(DE2-115_labs_vhdl)-PART5--实验四

4.实验四：计数器

Part I ：16位计数器

图4.1中所示的电路是使用了4个T触发器的4位同步计数器。这个计数器在其使能信号有效时每当到来一个上升沿时即计数一次，当清零信号有效时，计数器结果清零。试设计一个同类型的16位计数器。

图4.1 四位同步计数器

执行以下步骤：

1使用图4.1中给出的结构来写出一段16位计数器的VHDL代码，并编译。

2仿真工程来证实其正确性。

3扩展VHDL文件,使用按钮KEY0作为时钟输入,使用开关SW1和SW0作为使能信号和清零信号,使用7段码显示器HEX3—0来显示结果。进行必要的引脚分配并编译工程。

4在DE2-115开发板上实现这个电路，并通过拨动开关来测试电路功能。

5实现一个4位计数器并用Quartus II的RTL观测器来研究Quartus II是如何来综合该电路的。

Part 1代码：

counter_16：

  1 LIBRARY ieee;
  2 
  3 USE ieee.std_logic_1164.all;
  4 
  5 ENTITY counter_16 IS
  6 
  7 PORT (
  8 
  9       en   : IN STD_LOGIC;
 10 
 11       clk  : IN STD_LOGIC;
 12 
 13       clr  : IN STD_LOGIC;
 14 
 15       Qout    : OUT STD_LOGIC_VECTOR(15 DOWNTO 0)
 16 
 17 );
 18 
 19 END counter_16;
 20 
 21 ARCHITECTURE trans OF counter_16 IS
 22 
 23 COMPONENT t_ff IS
 24 
 25 PORT (
 26 
 27 t      : IN STD_LOGIC;
 28 
 29       clk    : IN STD_LOGIC;
 30 
 31       rst_n  : IN STD_LOGIC;
 32 
 33       qq      : OUT STD_LOGIC
 34 
 35 );
 36 
 37 END COMPONENT;
 38 
 39 SIGNAL q : STD_LOGIC_VECTOR(15 DOWNTO 0);
 40 
 41 -- X-HDL generated signals
 42 
 43 SIGNAL xhdl1 : STD_LOGIC;
 44 
 45 SIGNAL xhdl2 : STD_LOGIC;
 46 
 47 SIGNAL xhdl3 : STD_LOGIC;
 48 
 49 SIGNAL xhdl4 : STD_LOGIC;
 50 
 51 SIGNAL xhdl5 : STD_LOGIC;
 52 
 53 SIGNAL xhdl6 : STD_LOGIC;
 54 
 55 SIGNAL xhdl7 : STD_LOGIC;
 56 
 57 SIGNAL xhdl8 : STD_LOGIC;
 58 
 59 SIGNAL xhdl9 : STD_LOGIC;
 60 
 61 SIGNAL xhdl10 : STD_LOGIC;
 62 
 63 SIGNAL xhdl11 : STD_LOGIC;
 64 
 65 SIGNAL xhdl12 : STD_LOGIC;
 66 
 67 SIGNAL xhdl13 : STD_LOGIC;
 68 
 69 SIGNAL xhdl14 : STD_LOGIC;
 70 
 71 SIGNAL xhdl15 : STD_LOGIC;
 72 
 73 BEGIN
 74 
 75    u0 : t_ff
 76 
 77 PORT MAP (
 78 
 79          en,
 80 
 81          clk,
 82 
 83          clr,
 84 
 85          q(0)
 86 
 87 );
 88 
 89    xhdl1 <= en AND q(0);
 90 
 91    u1 : t_ff
 92 
 93 PORT MAP (
 94 
 95          xhdl1,
 96 
 97          clk,
 98 
 99          clr,
100 
101 q(1)
102 
103 );
104 
105    xhdl2 <= en AND q(0) AND q(1);
106 
107 u2 : t_ff
108 
109 PORT MAP (
110 
111 xhdl2,
112 
113          clk,
114 
115          clr,
116 
117          q(2)
118 
119 );
120 
121    xhdl3 <= en AND q(0) AND q(1) AND q(2);
122 
123 u3 : t_ff
124 
125 PORT MAP (
126 
127 xhdl3,
128 
129          clk,
130 
131          clr,
132 
133          q(3)
134 
135 );
136 
137    xhdl4 <= en AND q(0) AND q(1) AND q(2) AND q(3);
138 
139 u4 : t_ff
140 
141 PORT MAP (
142 
143 xhdl4,
144 
145          clk,
146 
147          clr,
148 
149          q(4)
150 
151 );
152 
153    xhdl5 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4);
154 
155 u5 : t_ff
156 
157 PORT MAP (
158 
159 xhdl5,
160 
161          clk,
162 
163          clr,
164 
165          q(5)
166 
167 );
168 
169    xhdl6 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5);
170 
171 u6 : t_ff
172 
173 PORT MAP (
174 
175 xhdl6,
176 
177          clk,
178 
179          clr,
180 
181          q(6)
182 
183 );
184 
185    xhdl7 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6);
186 
187 u7 : t_ff
188 
189 PORT MAP (
190 
191 xhdl7,
192 
193          clk,
194 
195          clr,
196 
197          q(7)
198 
199 );
200 
201    xhdl8 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7);
202 
203 u8 : t_ff
204 
205 PORT MAP (
206 
207 xhdl8,
208 
209          clk,
210 
211          clr,
212 
213          q(8)
214 
215 );
216 
217    xhdl9 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8);
218 
219 u9 : t_ff
220 
221 PORT MAP (
222 
223 xhdl9,
224 
225          clk,
226 
227          clr,
228 
229          q(9)
230 
231 );
232 
233    xhdl10 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9);
234 
235 u10 : t_ff
236 
237 PORT MAP (
238 
239 xhdl10,
240 
241          clk,
242 
243          clr,
244 
245          q(10)
246 
247 );
248 
249    xhdl11 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9) AND q(10);
250 
251 u11 : t_ff
252 
253 PORT MAP (
254 
255 xhdl11,
256 
257          clk,
258 
259          clr,
260 
261          q(11)
262 
263 );
264 
265    xhdl12 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9) AND q(10) AND q(11);
266 
267 u12 : t_ff
268 
269 PORT MAP (
270 
271 xhdl12,
272 
273          clk,
274 
275          clr,
276 
277          q(12)
278 
279 );
280 
281    xhdl13 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9) AND q(10) AND q(11) AND q(12);
282 
283 u13 : t_ff
284 
285 PORT MAP (
286 
287 xhdl13,
288 
289          clk,
290 
291          clr,
292 
293          q(13)
294 
295 );
296 
297    xhdl14 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9) AND q(10) AND q(11) AND q(12) AND q(13);
298 
299 u14 : t_ff
300 
301 PORT MAP (
302 
303 xhdl14,
304 
305          clk,
306 
307          clr,
308 
309          q(14)
310 
311 );
312 
313    xhdl15 <= en AND q(0) AND q(1) AND q(2) AND q(3) AND q(4) AND q(5) AND q(6) AND q(7) AND q(8) AND q(9) AND q(10) AND q(11) AND q(12) AND q(13) AND q(14);
314 
315 u15 : t_ff
316 
317 PORT MAP (
318 
319          xhdl15,
320 
321          clk,
322 
323          clr,
324 
325          q(15)
326 
327 );
328 
329    Qout <= q;
330 
331 END trans;

 

t_ff：

  1 LIBRARY ieee;
  2 
  3 USE ieee.std_logic_1164.all;
  4 
  5 ENTITY t_ff IS
  6 
  7 PORT (
  8 
  9 t      : IN STD_LOGIC;
 10 
 11       clk    : IN STD_LOGIC;
 12 
 13       rst_n  : IN STD_LOGIC;
 14 
 15       qq      : OUT STD_LOGIC
 16 
 17 );
 18 
 19 END t_ff;
 20 
 21 ARCHITECTURE trans OF t_ff IS
 22 
 23 -- Declare intermediate signals for referenced outputs
 24 
 25 SIGNAL q_xhdl0 : STD_LOGIC;
 26 
 27 BEGIN
 28 
 29 -- Drive referenced outputs
 30 
 31    qq <= q_xhdl0;
 32 
 33 PROCESS (clk)
 34 
 35 BEGIN
 36 
 37 IF (clk'EVENT AND clk = '1') THEN
 38 
 39 IF ((NOT(rst_n)) = '1') THEN
 40 
 41             q_xhdl0 <= '0';
 42 
 43 ELSE
 44 
 45 IF (t = '1') THEN
 46 
 47                q_xhdl0 <= NOT(q_xhdl0);
 48 
 49 ELSE
 50 
 51                q_xhdl0 <= q_xhdl0;
 52 
 53 END IF;
 54 
 55 END IF;
 56 
 57 END IF;
 58 
 59 END PROCESS;
 60 
 61 END trans;
 62 
 63 led_display：
 64 
 65 LIBRARY ieee;
 66 
 67 USE ieee.std_logic_1164.all;
 68 
 69 ENTITY led_display IS
 70 
 71 PORT (
 72 
 73       idig      : IN STD_LOGIC_VECTOR(3 DOWNTO 0);
 74 
 75    oseg      : OUT STD_LOGIC_VECTOR(6 DOWNTO 0)
 76 
 77 );
 78 
 79 END led_display;
 80 
 81 ARCHITECTURE trans OF led_display IS
 82 
 83 BEGIN
 84 
 85 PROCESS (idig)
 86 
 87 BEGIN
 88 
 89 CASE idig IS
 90 
 91 WHEN "0001" =>
 92 
 93             oseg <= "1111001";
 94 
 95 WHEN "0010" =>
 96 
 97             oseg <= "0100100";
 98 
 99 WHEN "0011" =>
100 
101             oseg <= "0110000";
102 
103 WHEN "0100" =>
104 
105             oseg <= "0011001";
106 
107 WHEN "0101" =>
108 
109             oseg <= "0010010";
110 
111 WHEN "0110" =>
112 
113             oseg <= "0000010";
114 
115 WHEN "0111" =>
116 
117             oseg <= "1111000";
118 
119 WHEN "1000" =>
120 
121             oseg <= "0000000";
122 
123 WHEN "1001" =>
124 
125             oseg <= "0011000";
126 
127 WHEN "1010" =>
128 
129             oseg <= "0001000";
130 
131 WHEN "1011" =>
132 
133             oseg <= "0000011";
134 
135 WHEN "1100" =>
136 
137             oseg <= "1000110";
138 
139 WHEN "1101" =>
140 
141             oseg <= "0100001";
142 
143 WHEN "1110" =>
144 
145             oseg <= "0000110";
146 
147 WHEN "1111" =>
148 
149             oseg <= "0001110";
150 
151 WHEN OTHERS =>
152 
153             oseg <= "1000000";
154 
155 END CASE;
156 
157 END PROCESS;
158 
159 END trans;

 

lab4_part1顶层：

  1 LIBRARY ieee;
  2 
  3 USE ieee.std_logic_1164.all;
  4 
  5 ENTITY lab4_part1 IS
  6 
  7 PORT (
  8 
  9       KEY   : IN STD_LOGIC_VECTOR(3 DOWNTO 0);
 10 
 11       SW     : IN STD_LOGIC_VECTOR(1 DOWNTO 0);
 12 
 13       HEX3   : OUT STD_LOGIC_VECTOR(6 DOWNTO 0);
 14 
 15       HEX2   : OUT STD_LOGIC_VECTOR(6 DOWNTO 0);
 16 
 17       HEX1   : OUT STD_LOGIC_VECTOR(6 DOWNTO 0);
 18 
 19       HEX0   : OUT STD_LOGIC_VECTOR(6 DOWNTO 0)
 20 
 21 );
 22 
 23 END lab4_part1;
 24 
 25 ARCHITECTURE trans OF lab4_part1 IS
 26 
 27 COMPONENT counter_16 IS
 28 
 29 PORT (
 30 
 31          en     : IN STD_LOGIC;
 32 
 33          clk    : IN STD_LOGIC;
 34 
 35          clr    : IN STD_LOGIC;
 36 
 37          Qout      : OUT STD_LOGIC_VECTOR(15 DOWNTO 0)
 38 
 39 );
 40 
 41 END COMPONENT;
 42 
 43 COMPONENT led_display IS
 44 
 45 PORT (
 46 
 47       idig      : IN STD_LOGIC_VECTOR(3 DOWNTO 0);
 48 
 49    oseg      : OUT STD_LOGIC_VECTOR(6 DOWNTO 0)
 50 
 51 );
 52 
 53 END COMPONENT;
 54 
 55 SIGNAL q          : STD_LOGIC_VECTOR(15 DOWNTO 0);
 56 
 57 -- Declare intermediate signals for referenced outputs
 58 
 59 SIGNAL HEX3_xhdl3 : STD_LOGIC_VECTOR(6 DOWNTO 0);
 60 
 61 SIGNAL HEX2_xhdl2 : STD_LOGIC_VECTOR(6 DOWNTO 0);
 62 
 63 SIGNAL HEX1_xhdl1 : STD_LOGIC_VECTOR(6 DOWNTO 0);
 64 
 65 SIGNAL HEX0_xhdl0 : STD_LOGIC_VECTOR(6 DOWNTO 0);
 66 
 67 BEGIN
 68 
 69 -- Drive referenced outputs
 70 
 71    HEX3 <= HEX3_xhdl3;
 72 
 73    HEX2 <= HEX2_xhdl2;
 74 
 75    HEX1 <= HEX1_xhdl1;
 76 
 77    HEX0 <= HEX0_xhdl0;
 78 
 79    z0 : counter_16
 80 
 81 PORT MAP (
 82 
 83          SW(1),
 84 
 85          KEY(0),
 86 
 87          SW(0),
 88 
 89          q
 90 
 91 );
 92 
 93    H0 : led_display
 94 
 95 PORT MAP (
 96 
 97          q(3 DOWNTO 0),
 98 
 99          HEX0_xhdl0
100 
101 );
102 
103    H1 : led_display
104 
105 PORT MAP (
106 
107          q(7 DOWNTO 4),
108 
109          HEX1_xhdl1
110 
111 );
112 
113    H2 : led_display
114 
115 PORT MAP (
116 
117          q(11 DOWNTO 8),
118 
119          HEX2_xhdl2
120 
121 );
122 
123    H3 : led_display
124 
125 PORT MAP (
126 
127          q(15 DOWNTO 12),
128 
129          HEX3_xhdl3
130 
131 );
132 
133 END trans;

 

仿真波形如下：

Part II ：思考题

1.)简化VHDL代码，使计数器的VHDL描述基于以下语句：

Q<=Q+1;

编制一个16位计数器，与之前的计数器比较所需的LE和最大允许的频率。使用RTL观测器来观察电路结构和第一部分中电路的区别。

2.)使用一个参数化模型库中的LPM模块来实现16位计数器，选择与以上设计一致的LPM设置，拥有使能和同步清零信号。比较这个版本的计数器与之前的设计。

3)设计一个在7段码显示器HEX0上连续闪烁数字0—9的的电路。每一个数字应该大概保持一秒钟。使用一个计数器来确定这一秒钟的间隔。这个计数器通过DE2-115上的50MHZ的时钟信号来增加计数。不要使用其他时钟信号，确保电路中所有的触发器直接由上述的50MHZ时钟信号驱动。

4.)设计并实现一个在HEX7—0上显示单词HELLO的电路。并使单词每间歇1秒就从右往左移动一次，预期显示如图4.2所示。

图4.2